Method and means for selectively crushing aggregate

ABSTRACT

The method and means of crushing soft aggregate out of harder aggregate by moving the aggregate between concaves and a powered rotor wherein the concaves are yieldable relative to the rotor and one of which is reciprocally powered to facilitate moving the aggregate under pressure while being confined between the concaves and the turning rotor. The concaves are pivotally connected together and a spring means engages the pivotal connection to bias it toward the rotor. The concave at the outlet of the working chamber is limited in its travel towards the rotor thereby allowing aggregate smaller than the spacing between the concave and the rotor to pass on through. The working chamber is tapered from the concave hinge point to the outlet to provide a restrictive discharge opening.

United States Patent Hankins [451 Aug.. 15, 1972 METHOD AND MEANS FOR SELECTIVELY CRUSHING AGGREGATE [22] Filed: April 15, 1970 [21] Appl. No.: 28,785

[52] U.S. Cl. "241/14, 241/27, 241/155, 241/240 511 Int. Cl. ..B02c l/08 [58] FieldofSearch ..24l/l4,27,29,155, 198, 198 A, 241/220, 221,222, 224, 225, 239, 240, 241,206, 237

[56] References Cited UNITED STATES PATENTS 2,063,829 12/1936 Riley ..241/240 2,588,180 3/1952 Traylor, Jr ..241/240 X 2,620,629 12/1952 Gouldie ..241/198 R X Liggett ..241/237 X Nevill ..241/237 X Primary Exaiminer-Granville Y. Custer, Jr. Attorney-Zarley, McKee & Thomte 5 7] ABSTRACT The method and means of crushing soft aggregate out of harder aggregate by moving the aggregate between concaves and a powered rotor wherein the concaves are yieldable relative to the rotor and one of which is reciprocally powered to facilitate moving the aggregate under pressure while being confined between the concaves and the turning rotor. The concaves are pivotally connected together and a spring means engages the pivotal connection to bias it toward the rotor. The concave at the outlet of the working chamber is limited in its travel towards the rotor thereby allowing aggregate smaller than the spacing between the concave and the rotor to passon through. The working chamber is tapered from the concave hinge point to the outlet to provide a restrictive discharge open- 8 Claims, 5 Drawing Figures METHOD AND MEANS FOR SELECTIVELY CRUSl-IING AGGREGATE Heretofore it has been time consuming and expensive to obtain good aggregate. Good aggregate is that aggregate which is sufficiently hard that it will give strength to concrete or the like to which it may be added as a construction material. The unsound or soft aggregate will be broken down only through chance or through being passed through a tumbling type machine a sufficient number of times such that it is likely it will be sooner or later subjected to forces it cannot tolerate. These machines are large, bulky, expensive and require high power relative to the output while also being expensive to maintain thus providing a generally inefficient system.

The method and machine of this invention moves the same type of aggregate material through a confining chamberwhile that material is under pressure. The aggregate material is forced through a restrictive discharge and there is no possible way for any particles to escape the combination of forces necessary to destroy the soft materials. The machine may be small and have a high output for the power required to operate it while requiring a minimum of maintenance.

The machine of this invention provides yieldable concaves embracing a powered rotor while each of the concaves in the rotor have hardened bearing surfaces for crushing the unsound or soft aggregate therebetween against the bearing surfaces or the sound or harder aggregate. Springs are provided on each of the concaves and at the pivotal connections therebetween biasing the concaves toward the rotor and one of the concaves at least includes a powered reciprocal cylinder operating to move the concave towards and away from the rotor as the concave moves a predetermined distance in each direction thereby facilitating the movement of the aggregate under pres sure while being confined through the machine.

This invention consists in the construction, arrangements and combination of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in the claims, and illustrated in the accompanying drawings in which:

FIG. 1 is a fragmentary end elevational view of the aggregate crushing machine of this invention.

FIG. 2 is a fragmentary elevational view taken along line 2 2 in FIG. 1.

FIG. 3 is an enlarged cross-sectional view taken along line 3 3 in FIG. 1.

FIG. 4 is a schematic of the powered cylinder circuitry; and

FIG. 5 is a fragmentary perspective view of the concaves and their hinge connection.

The aggregate material crusher of this invention is referred to in FIG. 1 generally by the reference numeral l0 and is seen to include a frame 12 having opposite end frame members including inwardly and downwardly extending portions 14 on opposite sides interconnected by horizontal portions 16 and 18 at the bottom and top respectively.

An aggregate hopper or chute 20 receives aggregate 22 and feeds it into the aggregate crushing machine over a volume sensing unit 24 on the inner wall of the chute 20.

The aggregate 22 includes hard or sound aggregate pieces 26 intermixed with soft or unsound larger aggregate pieces 28 and it is these pieces that will be crushed by the aggregate pieces 26 and operation of the machine 10 such that fines 30 will be discharged from the machine as a result of the crushing of the soft or unsound aggregate pieces 28. The soft or unsound aggregate pieces may be of any size but are shown larger in the drawings for purposes of illustration only.

A plurality of concaves may be pivotally intercom nected about a rotor and be yieldably biased towards the rotor. In FIG. 1 two concaves 32 and 34 are pivotally interconnected about a pivot shaft 36 and substantially embrace a powered rotor 38 over at least 180 of its circumference. The concave 32 includes a transversely extending inner bottom edge 40 positioned in close relationship to a corresponding edge on the concave 34. The concave 32 includes opposite end side walls 42 while the concave 34 has end walls 46. Each of the concaves 32 and 34 include bottom walls 48 on which bearing or wear plates 50 are secured to protect the bottom walls. Additionally the end walls 42 and 46 include wear or bearing plates 52.

The concaves 32 and 34form a working chamber 54 in which the rotor 38 is positioned. A V-shaped space 56 is formed between opposite and adjacent wall edges of end walls 42 and 46 and is closed by a plate 58 welded at 60 to the end wall 42 of the concave 32. A bearing sleeve 62 is welded to the plate 58 and embraces the pivotal shaft 36 to pivotally interconnect the concave 32 to the concave 34 at each end thereof.

The end walls 46 of the concave 34 include an opening 64 through which the shaft 36 is received. The shaft also extends outwardly through a portion 66 of a bracket 68 having anupwardly and inwardly extending portion 70 welded at 72 to the end wall 42 as best seen in FIG. 3. A collar 74 having a set screw 76 is rigidly carried by the bracket portion 66 while the set screw 76 engages the shaft 36.

The sleeve 62 rides on a bushing 80 while a bushing 82 embraces the sleeve 62 and is inside of a ring 84 having a downwardly extending link 86 connected to a guide rod 88 pivotally connected at its outer end to an L-shaped bracket 89 on the frame portion 14 as seen in FIG. 1. A cap 90 is rigid with the link 86 and the guide rod 88 and covers a threaded sleeve 92 which receives a bolt 94 inside of a coil spring 96. The bolt 94 and the coil spring 96 are anchored in a channel 98 on the frame portion 16.

The concave 34 includes a double acting powered cylinder 100 connected to the frameportion 14 to reciprocate the concave back and forth as an actuating control element 102 moves between limit switches 104 operatively connected to a solenoid valve 106 which in turn reverses the flow of fluid in the power cylinder 100 such that the concave moves a predetermined distance towards and away from the rotor 38.

The other concave 32 is biased inwardly towards the rotor 38 to a predetermined spacing therefrom as seen in FIG. 1 since a stop element 110 is provided for engagement with the frame portion 18. The biasing inwardly is accomplished by a coil spring 112 embracing a rod 114 extending between the frame portion 14 and engaging the concave 32.

The powered rotor 38 is driven by chain drive 120 connected to a shaft 122 extending from the rotor. Preferably the drive is a variable speed drive operatively connected to the volume sensing unit 24 in the hopper 20 such that the speed of the rotor can be varied as the volume of the material in the hopper varies.

Thus it is seen in operation the aggregate 22 including hard particles 26 and soft or unsound particles 28 will be fed into the hopper 20 and the speed of the rotor 38 will be controlled by the sensing unit 24 which will vary from the conditions prevailing for the aggregate material being worked upon at the time and this will depend upon size of the material and volume. The aggregate 22 falls by gravity into the inlet opening of the machine and between the rotor and the concave 34 which is reciprocating towards and away from the rotor 38 in response to the double acting cylinder 100. The movement of the concave 34 back and forth keeps the aggregate moving through the machine and results in all of the soft particles 28 being crushed by the harder particles 26 being compressed by the rotor 38 and the concave 34. Thus the rotor, concave and harder particles cooperate to pulverize the softer aggregate materials 28. The power cylinder may be either air or hydraulically operated depending on the aggregate material being worked upon and other conditions of use.

The aggregate material as it passes on through the machine 10 may displace outwardly the concaves 32 and 34 in the area of the pivotal shaft 36 connecting the concaves together as the coil spring 96 will yield as necessary but only after the particles 28 have been pulverized. The strength of the springs may be appropriately selected for the conditions existing The concave 32 at the discharge end of the machine is normally biased towards the rotor to at least as far as the stop 110 will permit to provide a minimum spacing between the rotor and the concave bearing plate 50 for hard particles 26 of the predetermined size to pass therebetween and out of the machine onto a screen 130. The soft or unsound particles 28 have been crushed or pulverized into fines 30 which will pass through the screen 130 leaving the sound or hard particles 26.

In the schematic drawing of FIG. 4, a hydraulic system is shown for the power cylinder 100 and includes a pump 132, a reservoir 134 and a relief valve 136. As shown the system will continuously operate such that the cylinder will operate in one direction and then after a predetermined length of travel controlled by the limit switches 104 it will move in the opposite direction to keep the concave 34 continuously moving inwardly and outwardly relative to the rotor 38. The speed of the rotor may be appropriately set for existing conditions of use.

Accordingly, the method of crushing soft unsound aggregate material by the machine described involves the reciprocation of one of the concaves powered by a double. acting cylinder and thus the aggregate material is moved towards the restricted outlet while it is confined and under pressure. Initial pressure is built up by reciprocating concave and the small concave 32 with its diminishing chamber and restrictive discharge near the horizontal center line of the rotor retains this pressure until material leaves the machine.

All working conditions are. under full control at all times and include feed, confinement, pressure, movement, and discharge conditions. Each and every particle being processed in the machine is in a given place at a given time because it has been forced there. It cannot move until it is forced to do so and then it has to move or be broken and crushed. It is seen that the best possible results are obtainable with this machine and method with the least complicated machine to give high production with low power,- cost and maintenance requirements.

lclaim: I

l. A selective aggregate crusher comprising,

a frame yieldably supporting a plurality of hinged together concaves defining a working chamber in which a powered rotor is positioned,

said working chamber having an inlet opening and a discharge outlet opening, said inlet and discharge outlet openings being located on opposite sides of said rotor, said working chamber tapering from at least the hinged connection of said concaves closest to said outlet opening to said outlet openmg,

said concaves having such a size to cumulatively cover at least around said rotor,

said rotor having a stationary axis of rotation and said concaves being yieldable relative to said rotor,

said rotor and said concaves each having opposing bearing surfaces whereby as aggregate material is moved from said inlet opening to said outlet opening between said rotor and said concaves it is moved while being confined and under pressure, and

one of said concaves including a double acting power cylinder connected between it and said frame for pivoting said one concave towards and away from said rotor in response to a control means operable by said one concave upon moving a predetermined distance towards and away from said rotor to reverse directions of movement of said cylinder and one concave.

2. A selective aggregate crusher comprising,

a frame yieldably supporting a plurality of hinged together concaves defining a working chamber in which a powered rotor is positioned,

said working chamber having an inlet opening and a discharge outlet opening, said inlet and discharge outlet openings being located on opposite sides of said rotor, said working chamber tapering from at least the hinged connection of said concaves closest to said outlet opening to said outlet opening,

said concaves having such a size to cumulatively cover at least 180 around said rotor,

said rotorhaving a stationary axis of rotation and said concaves being yieldable relative to said rotor,

said rotor and said concaves each having opposing bearing surfaces whereby as aggregate material is moved from said inlet opening to said outlet opening between said rotor and said concaves it is moved while being confined and under pressure, and

said plurality of concaves hingeably connected together including two concaves hinged together at adjacent ends and having an axis of pivotable movement about a shaft yieldably supported by said frame whereby said two concaves are free to move towards and away from said rotor in response to appropriate pressure on said two concaves in said working chamber.

3. The structure of claim 2 wherein a guide rod is connected to said shaft and extends substantially perpendicular thereto and is secured to said frame remotely of said shaft.

4. The structure of claim 2 wherein one of said two concaves includes a spring means extending between said one concave and said frame to yieldably urge said one concave towards said rotor, and a two-way power cylinder is connected between said other concave and said frame for continuously and alternately pivoting said other concave towards and away from said rotor.

5. The structure of claim 4 wherein said control means is associated with said other concave and said power cylinder such that it is operable by said other concave upon moving a predetermined distance towards and away from said rotor to reverse directions of movement of said cylinder and said other concave.

6. The structure of claim 5, wherein said one concave includes a stop means for limiting the travel of said one concave towards said rotor whereby aggregate material having a smaller size than the minimum distance between said rotor and one concave may pass out of said discharge opening;

7. The method of selectively crushing unsound soft material contained in hard aggregate materials including the steps of,

feeding and confining. aggregate in a working chamber tapering towards a restricted outlet and defined by a plurality of concaves pivoted together and yieldably biased towards a rotating rotor with the concave at the outlet being closely spaced to said rotor with only rotational clearance therebetween, and

crushing said unsound soft material between pieces of hard aggregate and said hard aggregate and said concaves and rotor by continuously moving the aggregate including the unsound soft material in the working chamber while maintaining continuous pressure on the aggregate as it is confined by the concaves floating relative to the rotor as the materials flow through the working chamber whereby said concaves are continuously reciprocated towards and away from said rotor by said hard aggregate being forced between said concaves and said rotor.

8. The method of claim 7 wherein the step of moving the aggregate in the working chamber is accomplished by reciprocating one of the concaves towards and away from the rotating rotor. 

2. A selective aggregate crusher comprising, a frame yieldably supporting a plurality of hinged together concaves defining a working chamber in which a powered rotor is positioned, said working chamber having an inlet opening and a discharge outlet opening, said inlet and discharge outlet openings being located on opposite sides of said rotor, said working chamber tapering from at least the hinged connection of said concaves closest to said outlet opening to said outlet opening, said concaves having such a size to cumulatively cover at least 180* around said rotor, said rotor having a stationary axis of rotation and said concaves being yieldable relative to said rotor, said rotor and said concaves each having opposing bearing surfaces whereby as aggregate material is moved from said inlet opening to said outlet opening between said rotor and said concaves it is moved while being confined and under pressure, and said plurality of concaves hingeably connected together including two concaves hinged together at adjacent ends and having an axis of pivotable movement about a shaft yieldably supported by said frame whereby said two concaves are free to move towards and away from said rotor in response to appropriate pressure on said two concaves in said working chamber.
 3. The structure of claim 2 wherein a guide rod is connected to said shaft and extends substantially perpendicular thereto and is secured to said frame remotely of said shaft.
 4. The structure of claim 2 wherein one of said two concaves includes a spring means extending between said one concave and said frame to yieldably urge said one concave towards said rotor, and a two-way power cylinder is connected between said other concave and said frame for continuously and alternately pivoting said other concave towards and away from said rotor.
 5. The structure of claim 4 wherein said control means is associated with said other concave and said power cylinder such that it is operable by said other concave upon moving a predetermined distance towards and away from said rotor to reverse directions of movement of said cylinder and said other concave.
 6. The structure of claim 5, wherein said one concave includes a stop means for limiting the travel of said one concave towards said rotor whereby aggregate material having a smaller size than the minimum distance between said rotor and one concave may pass out of said discharge opening.
 7. The method of selectively crushing unsound soft material contained in hard aggregate materials including the steps of, feeding and confiNing aggregate in a working chamber tapering towards a restricted outlet and defined by a plurality of concaves pivoted together and yieldably biased towards a rotating rotor with the concave at the outlet being closely spaced to said rotor with only rotational clearance therebetween, and crushing said unsound soft material between pieces of hard aggregate and said hard aggregate and said concaves and rotor by continuously moving the aggregate including the unsound soft material in the working chamber while maintaining continuous pressure on the aggregate as it is confined by the concaves floating relative to the rotor as the materials flow through the working chamber whereby said concaves are continuously reciprocated towards and away from said rotor by said hard aggregate being forced between said concaves and said rotor.
 8. The method of claim 7 wherein the step of moving the aggregate in the working chamber is accomplished by reciprocating one of the concaves towards and away from the rotating rotor. 